Open Access
28 October 2022 Emerging SARS-CoV-2 Variants and Subvariants: Challenges and Opportunities in the Context of COVID-19 Pandemic
Smaranika Rahman, Md. Jamal Hossain, Zabun Nahar, Mohammad Shahriar, Mohiuddin Ahmed Bhuiyan, Md. Rabiul Islam
Author Affiliations +

The COVID-19 pandemic has become the most devastating pandemic of the 21st century since its appearance in December 2019. Like other RNA viruses, continuous mutation is common for coronavirus to create several variants and subvariants. The main reason behind this mutation and evolvement of SARS-CoV-2 was its structural spike (S) glycoprotein. Coronavirus has become a threat to global public health due to its high mutation capability and antibody neutralizing capacity. According to the World Health Organization (WHO), there are 5 major variants of concern (VOC) are Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529). Recently, different Omicron subvariants have gained worldwide dominance, such as BA.1, BA.2, BA.3, BA.4, and BA.5. However, there is a discernible drop in this symptomatic sickness globally due to the success of numerous monoclonal antibodies and vaccinations. Here we also discussed the currently dominant Omicron subvariants and the effectiveness of antiviral agents and vaccines. Based on the available data and our knowledge, we can suggest that the global healthcare organizations can decide on the declaration of the end of the pandemic phase of COVID-19 soon; however, the covid-19 will continue.


Coronaviruses belong to a class of encapsulated positive single-stranded RNA viruses that have a diverse spectrum of natural hosts. They can infect a wide range of animals and humans.1,2 Tyrrell and Bynoe isolated the viruses from the common-cold patients and later gave them the name coronavirus in 1966 for their crown-like appearance.3 The first SARS-CoV virus emerged suddenly in China in 2002 to 2003 that killed 813 of 8,809 affected people in 29 countries or regions.4 After that, in 2012, the MERS-CoV emerged as a human disease with a high case-fatality rate.5 The ongoing COVID-19 is the largest zoonotic pandemic after the Spanish influenza pandemic.6 It was initially called Wuhan pneumonia due to the location and pneumonia symptoms. The World Health Organization (WHO) renamed this viral infection “COVID-19” on February 12, 2020.7 The International Committee on Taxonomy of Viruses (ICTV) proposed this virus as SARS-CoV-2 since it belongs to the severe acute respiratory syndrome-associated coronavirus category.8 The SARS-CoV-2 virus has been evolving since its discovery in December 2019. As several variants are developing around the world, the WHO classified those variants as variants of concern (VOC), variants under monitoring (VUM), and variants of interest (VOI).9

SARS-CoV-2 Variants and Subvariants

RNA viruses are more likely than DNA viruses to develop variants. COVID-19 replication is widespread since it is an RNA virus.10 In this case, the structural spike (S) glycoprotein plays the most important role, and mutations in this S-glycoprotein led to the emergence of VOC by increasing angiotensin-converting enzyme-2 (ACE-2) receptor affinity, resistance to neutralizing antibodies, viral replication, infectivity, higher transmissibility, and immune escape, resulting in increased reinfection risk and severity of reinfection.11 Five reported VOCs are: Alpha (B.1.1.7; UK, Sep-2020); Beta (B.1.351; South Africa, May-2020); Gamma (P.1; Brazil, November 2020); Delta (B.1.617.2; India, October 2020); and Omicron (B.1.1.529; several countries, November 2021).9,12,13

Among the 5 VOCs, the Omicron has a unique feature with a total of 30 signature mutations.13 Among them, 23 are bold-faced mutations.13 These mutations are different from others variants.13 The percentage of Omicron infection in Africa reached ∼90% within the first 25 days after the first identification in November 2021. However, we have seen the Beta variant responsible for ∼50% infection rate within roughly 100 days, and the Delta variant contributed ∼80% infection within approximately 100 days.14 According to an artificial intelligence (AI) model, the Omicron variant was thought to be 2.8 times more transmissible than the Delta, eluding current immunizations by nearly 90% and drastically reducing monoclonal antibody efficacy (mAbs).15 Until January 8, 2022, it was distributed in 150 countries or territories, resulting in 552,191 confirmed cases and 115 deaths [18].16 Omicron has 5 sublineages such as BA.1, BA.2, BA.3, BA.4, and BA.5.9 The ancestral lineage of the Omicron variant appears to be B.1.1.529, followed by the BA.1 sublineage, which looks to be the most similar to B.1.1.529 and BA.3 is the combined form of BA.1 and BA.2 sublineages.16,17 A study revealed that BA.1 has 37 mutations in the spike protein, BA.2 has 31 mutations, BA.3 has 33 mutations with 21 common mutations in all 3 lineages.16 The receptor-binding domain (RBD) interacts with host ACE-2 to induce infection. Also, it is a prominent target for vaccines and antiviral drug development.18 There are 15 mutations in RBD of Omicron BA.1 subvariants, whereas we observed 12 mutations in RBD of Omicron BA.2 and BA.3 variants. Also, there are some common mutations among the sub-variants of Omicron.19 According to a study by Chen and Wei, the BA.2 subvariant of Omicron is 1.5 and 4.2 times more infectious than BA.1 subvariants and Delta variants, respectively.19 It also revealed that it has a 30% higher chance of eluding current vaccinations than BA.1 and the reinfection capacity of the patients who had recovered from BA.1.19.19 BA.2 Omicron is also known as the stealth Omicron because its genetic alterations make it difficult to distinguish from Delta using PCR testing.20 According to the WHO, it is now the most prevalent strain of COVID-19 worldwide and the virus’s most transmissible version to date.20,21 According to the Centers for Disease Control and Prevention (CDC), it is the most common form of COVID-19 in the USA, accounting for 74.4% of all COVID-19 occurrences till April 16, 2022.22

The WHO categorized BA.4, BA.5 (BA.1 and BA.2 sister lineages), and a few other BA.2 sublineages as VOC sublineages under monitoring (VOC-LUM). BA.2.12.1, BA.4 and BA.5 subvariants appear to escape antibody responses among fully vaccinated and boosted individuals and those who had previous Covid-19 infection.23 The WHO will review the global epidemiology of VOC-LUM, monitor and track global spread, assist more laboratory investigations, review characteristics of the VOC-LUM and provide a separate label in case those are substantially different.9 Moreover, the member states are asked to perform more investigations and research to unveil the viral characteristics of these VOC-LUM. A table of WHO-labeled Omicron subvariants is demonstrated in Table 1.

Table 1.

Currently identified Omicron subvariants.


Hybrid or Recombinant Forms of SARS-CoV-2 Subvariants

People are now concerned about several other hybrid or recombinant forms. Omicron’s XE subvariant has now surpassed this.37 According to Consumer News and Business Channel (CNBC), the first case of XE was discovered in the UK on January 19, 2022, and as of April 12, 2022, 1,125 cases of XE have been discovered in the UK.24 Cases have also been reported in Thailand, India, China, Japan, and Israel, but no cases have been detected in the United States as of April 12, 2022.38 XE is a recombinant virus that contains parts of Omicron strains, BA.1, as well as the more infectious BA.2 subvariant, popularly known as “Stealth Omicron,” and is effectively a mixture of genetic material from 2 viruses.39 According to United Kingdom Health Security Agency (UKHSA) data, XE has a growth rate of 9.8% higher than BA.2, whereas the WHO has put the figure at 10% so far.38 Professor Susan Hopkins, UKHSA’s main medical advisor, stated that “at this time, there is insufficient evidence to form conclusions concerning transmissibility, severity or vaccine effectiveness.”40 Rather than XE, there are several other BA.1 and BA.2 recombinants, including XQ in the UK, XG in Denmark, XJ in Finland, and XK in Belgium.41 Furthermore, another controversial recombinant known as “Deltacron” (formally referred to as XD and XF) is usually the recombination variations of Delta and Omicron and appears to have a genetic sequence mostly identical to Delta, but with features of the spike protein from Omicron BA.1.41 It was originally discovered in France in mid-February, and according to the UKHSA, fewer than 40 instances of XF have been discovered, all in the UK. Although no cases of XD have been documented in the UK, 49 cases, predominantly in France, have been reported to global databases.42

Effectiveness of Potential Therapeutic Agents Against Omicron Subvariants

Recently, Omicron BA.2 has become the most common subvariant worldwide, with recombinant subvariants; for example, XE was a dominating variant in several countries, particularly the UK. A recent study found that boosting with Pfizer or Moderna, rather than 2 doses of Pfizer or AstraZeneca, offered a significant increase in protection.43 On the contrary, the subvariants BA.1 and BA.2 didn’t show much effectiveness against mAbs from Eli Lilly, Regeneron, AstraZeneca, Celltrion, Rockefeller University except sotrovimab developed by GlaxoSmithKline.19

According to WHO, a new variety known as the XE subvariant has evolved and is now classified as a new VOC.9 Although more research and data are needed before drawing any conclusions regarding the efficacy of the current COVID-19 therapy option, there is still hope that the new recombinant versions are not as dangerous as previously thought.44 There were XA, XB, XC, and XD subvariants before XE, but none of them constituted a threat to global health.30 Furthermore, following the identification of the XE subvariant on January 19, 2022, the number of hospitalizations due to this variety did not increase significantly; however, the Delta and Omicron variants caused a catastrophic pandemic within the first 2 weeks.45 Moreover, according to recent data, vaccine effectiveness against symptomatic infection was 9% and 13% for BA.1 and BA.2 subvariants, respectively.45 However, the rates can be improved to 63% for BA.1 and 70% for BA.2 at 2 weeks after a third booster dose.45 The recombination of either Omicron sublineages or Omicron and Delta sublineages is one of the new developing variations. Therefore, their effectiveness against vaccines is assumed to be the same. The effectiveness of potential therapeutic monoclonal antibodies (mAbs), antiviral agents, vaccines, and combinations of some monoclonal antibodies against recent WHO-labeled COVID-19 Omicron subvariants is shown in Table 2.

Table 2.

Effectiveness of potential therapeutic monoclonal antibodies (mAbs), antiviral agents, vaccines and combinations of some monoclonal antibodies.


Ending of Pandemic Phase and Moving Back to Regular Life

Healthcare systems, educational institutions and communities, and the global economy have faced a devastating situation since the introduction of the ongoing COVID-19 pandemic.5257 The world has been dealing with the devastating pandemic crisis created by the 5 most hazardous VOCs by expanding vaccination facilities and raising public awareness about health safety guidelines.58 Year 2020 was challenging to approach therapeutic options and develop vaccines against COVID-19. In 2021, the world has got several effective vaccines and anti-viral drugs to fight coronavirus.59 Countries across the world are giving third or booster doses of vaccines, and the Omicron variant have infected a huge population worldwide.60 In earlier, we assumed that the pandemic phase of COVID-19 will end after the massive wave due to the Omicron variant.61 The present global SARS-CoV-2 immunity is at a high level than ever by the combined effect of natural immunity and vaccination efforts. However, there might have chances to evolve some deadly new variants of SARS-CoV-2 in the close future. Some countries might face rising peaks of SARS-CoV-2 transmission during their winter months. Moreover, we have some lessons from the earlier influenza pandemics and we know how the earlier deadly pandemics were brought under control. Therefore, healthcare authorities across the world need to revise and update their responses to the COVID-19 pandemic. They can emphasize new molecular, phylogenetic, and pathogenetic insights to explain and understand the efficacy of current vaccines and the potential risk of new variants.62 Also, they should consider the declaration of the end of the pandemic phase of COVID-19 based on the previous experiences, present lessons, and nature of the coronavirus variants.

However, the future SARS-CoV-2 variants and subvariants might have less impact on humans. The healthcare authorities and people will face future waves with updated vaccines, improved antivirals, and well-adopted preventive techniques. Special countermeasures need to take for the vulnerable populations during the COVID-19 waves. Therefore, we can expect that the COVID-19 pandemic will be ended soon to turn back to regular life. Our healthcare systems will develop and adopt effective policies to manage future COVID-19 waves. The extra precautionary period of COVID-19 will be over soon. Therefore, the international healthcare authorities should prepare an integrated action plan to end the pandemic phase of COVID-19. They should take more initiatives to engage the general population in vaccination programs and health safety measures. Also, they should take an activity plan for research and closely observe the viral mutations to assess the impact of new variants on human health. Moreover, they should support fragile healthcare systems to protect the health of every people from any future pandemics across the world.

Author Contributions

Smaranika Rahman, Md. Jamal Hossain, and Zabun Nahar reviewed articles, collected information and wrote the first draft. Mohammad Shahriar and Mohiuddin Ahmed Bhuiyan edited the manuscript, gave intellectual inputs in the revised manuscript. Md. Rabiul Islam supervised the whole work and revised the manuscript. All the authors reviewed and approved the final submission.

Disclosures and Ethics

Not applicable to this article.



Weiss SR , Leibowitz JL. Coronavirus pathogenesis. Adv Virus Res. 2011;81:85–164. Google Scholar


Mohapatra RK , Tiwari R , Sarangi AK , Islam MR , Chakraborty C , Dhama K. Omicron (B.1.1.529) variant of SARS-CoV-2: concerns, challenges, and recent updates. J Med Virol. 2022;94:2336–2342. Google Scholar


Tyrrell DA , Bynoe ML. Cultivation of viruses from a high proportion of patients with colds. Lancet. 1966;1:76–77. Google Scholar


Morens DM , Breman JG , Calisher CH , et al. The origin of COVID-19 and why it matters. Am J Trop Med Hyg. 2020;103:955–959. Google Scholar


Ahammad I , Hossain MU , Rahman A , et al. Wave-wise comparative genomic study for revealing the complete scenario and dynamic nature of COVID-19 pandemic in Bangladesh. PLoS One. 2021;16:e0258019. Google Scholar


Johnson NP , Mueller J. Updating the accounts: global mortality of the 1918-1920 “Spanish” influenza pandemic. Bull Hist Med. 2002;76:105–115. Google Scholar


Liu YC , Kuo RL , Shih SR. COVID-19: the first documented coronavirus pandemic in history. Biomed J. 2020;43:328–333. Google Scholar


Dhama K , Khan S , Tiwari R , et al. Coronavirus disease 2019-COVID-19. Clin Microbiol Rev. 2020;33:e00028. Google Scholar


World Health Organization. Tracking SARS-CoV-2 variants. 2022. Accessed June 24, 2022. Google Scholar


Lauring AS , Hodcroft EB. Genetic variants of SARS-CoV-2-What do they mean? JAMA. 2021;325:529–531. Google Scholar


Hirabara SM , Serdan TDA , Gorjao R , et al. SARS-COV-2 variants: differences and potential of immune evasion. Front Cell Infect Microbiol. 2022;11:781429. Google Scholar


Rahman FI , Ether SA , Islam MR. The “Delta Plus” COVID-19 variant has evolved to become the next potential variant of concern: mutation history and measures of prevention. J Basic Clin Physiol Pharmacol. 2021;33:109–112. Google Scholar


Sohan M , Hossain MJ , Islam MR . The SARS-CoV-2 omicron (B.1.1.529) variant and effectiveness of existing vaccines: What we know so far. J Med Virol. 2022;94:1796–1798. Google Scholar


He X , Hong W , Pan X , Lu G , Wei X. SARS-CoV-2 omicron variant: characteristics and prevention. MedComm. 2021;2:838–845. Google Scholar


Chen J , Wang R , Gilby NB , Wei GW. Omicron variant (B.1.1.529): infectivity, vaccine breakthrough, and antibody resistance. J Chem Inf Model. 2022;62:412–422. Google Scholar


Desingu PA , Nagarajan K , Dhama K . Emergence of omicron third lineage BA.3 and its importance. J Med Virol. 2022;94:1808–1810. Google Scholar


Desingu PA , Nagarajan K. , Omicron BA. , 2 lineage spreads in clusters and is concentrated in Denmark. J Med Virol. 2022;94:2360–2364. Google Scholar


Lan J , Ge J , Yu J , et al. Structure of the SARS-CoV-2 spike receptor-binding domain bound to the ACE2 receptor. Nature. 2020;581:215–220. Google Scholar


Chen J , Wei GW. Omicron BA.2 (B.1.1.529.2): high potential to becoming the next dominating variant. ArXiv [Preprint], arXiv:2202.05031v1; 2022. Google Scholar


The New York Times. ‘Stealth’ Omicron is stealthy no more: what’s known about the BA.2 variant. 2022. Accessed April 24, 2022. Google Scholar


Islam MR , Hossain MJ . Detection of SARS-CoV-2 omicron (B.1.1.529) variant has created panic among the people across the world: what should we do right now? J Med Virol. 2022;94:1768–1769. Google Scholar


Center for Disease Control and Prevention. COVID data tracker. 2022. Accessed April 25, 2022. Google Scholar


Rotondo JC , Martini F , Maritati M , et al. Advanced Molecular and immunological diagnostic methods to detect SARS-CoV-2 infection. Microorganisms. 2022;10:1193. Google Scholar


Kumar S , Karuppanan K , Subramaniam G . Omicron (BA.1) and sub-variants (BA.1.1, BA.2, and BA.3) of SARS-CoV-2 spike infectivity and pathogenicity: A comparative sequence and structural-based computational assessment. J Med Virol. Published online June 9, 2022. doi: Google Scholar


Wilson C. Omicron still on the rise. New Sci. 2022;255:7. Google Scholar


Public health Ontario. SARS-CoV-2 Omicron variant sub-lineage BA.3. 2022. Accessed April 25, 2022. Google Scholar


Kumar S , Thambiraja TS , Karuppanan K , Subramaniam G. Omicron and delta variant of SARS-CoV-2: a comparative computational study of spike protein. J Med Virol. 2022;94:1641–1649. Google Scholar


Veneti L , Bøås H , Bråthen Kristoffersen A , et al. Reduced risk of hospitalisation among reported COVID-19 cases infected with the SARS-CoV-2 omicron BA.1 variant compared with the delta variant, Norway, December 2021 to January 2022. Euro Surveill. 2022;27:2200077. Google Scholar


Wang Q , Guo Y , Iketani S , et al. Antibody evasion by SARS-CoV-2 Omicron subvariants BA.2.12.1, BA.4, & BA.5. Nature. Published online July 5, 2022. doi: Google Scholar


Eggink D , Andeweg SP , Vennema H , et al. Increased risk of infection with SARS-CoV-2 omicron BA.1 compared with delta in vaccinated and previously infected individuals, the Netherlands, 22 November 2021 to 19 January 2022. Euro Surveill. 2022;27:2101196. Google Scholar


Hachmann NP , Miller J , Collier AY , et al. Neutralization escape by SARS-CoV-2 omicron subvariants BA.2.12.1, BA.4, and BA.5. N Engl J Med. 2022;387:86–88. Google Scholar


Bellusci L , Grubbs G , Zahra FT , et al. Antibody affinity and cross-variant neutralization of SARS-CoV-2 omicron BA.1, BA.2 and BA.3 following third mRNA vaccination. Nat Commun. 2022;13:4617. Google Scholar


Huang M , Wu L , Zheng A , et al. Atlas of currently available human neutralizing antibodies against SARS-CoV-2 and escape by Omicron sub-variants BA.1/BA.1.1/BA.2/BA.3. Immunity. 2022;55:1501–1514.e3. Google Scholar


Kurhade C , Zou J , Xia H , et al. Neutralization of omicron BA.1, BA.2, and BA.3 SARS-CoV-2 by 3 doses of BNT162b2 vaccine. Nat Commun. 2022;13:3602. Google Scholar


Iketani S , Liu L , Guo Y , et al. Antibody evasion properties of SARS-CoV-2 omicron sublineages. Nature. 2022;604:553–556. Google Scholar


Ai J , Wang X , He X , et al. Antibody evasion of SARS-CoV-2 Omicron BA.1, BA.1.1, BA.2, and BA.3 sub-lineages. Cell Host Microbe. Published online May 8, 2022. doi: Google Scholar


Rabiul Islam M , Nasreen W , Anjum R , et al. Characteristics of the SARS-CoV-2 Omicron (B.1.1.529) Variant and Emerging Impact on Global Public Health. Clin Pathol. 2022;15:2632010X221124908. Google Scholar


CNBC. New omicron XE Covid variant first detected in the UK spreads to Japan as cases rise. 2022. Accessed April 25, 2022. Google Scholar


Forbes, Forbes. Here’s what we know about Omicron XE — The new Covid variant found in the U.K. 2022. Accessed April 25, 2022.—the-new-covid-variant-found-in-the-uk/?sh=721d9ba62a8c Google Scholar


CNBC. UK has detected a new Covid variant. Here’s what we know so far about omicron XE. Accessed April 25, 2022. Google Scholar


Basky G , Vogel L. XE, XD & XF: what to know about the omicron hybrid variants. CMAJ. 2022;194:E654-E655. Google Scholar


Rahimi F , Talebi Bezmin Abadi A. Detection of the XE subvariant of SARS-CoV-2: a perspective. Int J Surg. 2022;101:106642. Google Scholar


Andrews N , Stowe J , Kirsebom F , et al. Covid-19 vaccine effectiveness against the omicron (B.1.1.529) variant. N Engl J Med. 2022;386:1532–1546. Google Scholar


Mahase E. Omicron sub-lineage BA.2 may have “substantial growth advantage,” UKHSA reports. BMJ. 2022;376:o263. Google Scholar


Cao Y , Yisimayi A , Jian F , et al. BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by omicron infection. Nature. 2022;608:593–602. Google Scholar


Takashita E , Yamayoshi S , Simon V , et al. Efficacy of antibodies and antiviral drugs against omicron BA.2.12.1, BA.4, and BA.5 subvariants. N Engl J Med. 2022;387:468–470. Google Scholar


Hentzien M , Autran B , Piroth L , et al. A monoclonal antibody stands out against omicron subvariants: a call to action for a wider access to bebtelovimab. Lancet Infect Dis. Published online July 18, 2022. doi: Google Scholar


Yamasoba D , Kosugi Y , Kimura I , et al. Neutralisation sensitivity of SARS-CoV-2 omicron subvariants to therapeutic monoclonal antibodies. Lancet Infect Dis. 2022;22:942–943. Google Scholar


Ai J , Wang X , He X , et al. Antibody evasion of SARS-CoV-2 omicron BA.1, BA.1.1, BA.2, and BA.3 sub-lineages. Cell Host Microbe. 2022;30:1077–1083.e4. Google Scholar


Yu J , Collier AY , Rowe M , et al. Neutralization of the SARS-CoV-2 omicron BA.1 and BA.2 variants. N Engl J Med. 2022;386:1579–1580. Google Scholar


Zou Y , Huang D , Jiang Q , Guo Y , Chen C. The vaccine efficacy against the SARS-CoV-2 omicron: a systemic review and meta-analysis. Front Public Health. 2022;10:940956. Google Scholar


Daria S , Islam MR. Increased suicidal behaviors among students during COVID-19 lockdowns: a concern of student’s mental health in Bangladesh. J Affect Disord Rep. 2022;8:100320. Google Scholar


Hossain MJ , Ahmmed F , Sarker MMR , et al. Factors associated with underprivileged E-Learning, session jam phobia, and the subsequent mental distress among students following the extended university closure in Bangladesh. Front Public Health. 2022;9:807474. Google Scholar


Hossain MJ , Soma MA , Bari MS , Emran TB , Islam MR. COVID-19 and child marriage in Bangladesh: emergency call to action. BMJ Paediatr Open. 2021;5:e001328. Google Scholar


Ether SA , Emon FA , Roknuzzaman A , Rakibuzzaman M , Rahman FI , Islam MR. A cross-sectional study of COVID-19-related knowledge, risk perceptions, and preventive practices among pharmacy students in Bangladesh. SAGE Open Med. 2022;10:20503121211073014. Google Scholar


Islam MR , Quaiyum S , Pakhe SA , ReponMAU Bhuiyan MA. Dataset concerning the mental health of healthcare professionals during COVID-19 pandemic in Bangladesh. Data Brief. 2021;39:107506. Google Scholar


Islam MR , Hossain MJ. Increments of gender-based violence amid COVID-19 in Bangladesh: a threat to global public health and women’s health. Int J Health Plann Manage. 2021;36:2436–2440. Google Scholar


Islam S , Islam T , Islam MR. New Coronavirus variants are creating more challenges to global healthcare system: A Brief Report on the current knowledge. Clin Pathol. 2022;15:2632010X221075584. Google Scholar


Islam MR. Urgent call for mass immunization against coronavirus in Bangladesh. Sci Prog. 2021;104:368504211058562. Google Scholar


Bari MS , Hossain MJ , Ahmmed F , et al. Knowledge, perception, and willingness towards immunization among Bangladeshi population during COVID-19 vaccine rolling period. Vaccines. 2021;9:1449. Google Scholar


Daria S , Islam MR. The SARS-CoV-2 omicron wave is indicating the end of the pandemic phase but the COVID-19 will continue. J Med Virol. 2022;94:2343–2345. Google Scholar


Rotondo JC , Martini F , Maritati M , et al. SARS-CoV-2 infection: new molecular, phylogenetic, and pathogenetic insights. Efficacy of current vaccines and the potential risk of variants. Viruses. 2021;13:1687. Google Scholar
© The Author(s) 2022
Smaranika Rahman, Md. Jamal Hossain, Zabun Nahar, Mohammad Shahriar, Mohiuddin Ahmed Bhuiyan, and Md. Rabiul Islam "Emerging SARS-CoV-2 Variants and Subvariants: Challenges and Opportunities in the Context of COVID-19 Pandemic," Environmental Health Insights 16(1), (28 October 2022).
Received: 24 June 2022; Accepted: 9 September 2022; Published: 28 October 2022
public health
SARS-CoV-2 subvariants
Back to Top