Early Omicron Infections Won’t Protect Against New Subvariants: Study

The study found that Omicron subvariants BA.4/BA.5 and BA.2.12.1 are more transmissible than BA.1 and BA.2.

Omicron subvariants reinfections

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Omicron variants like BA.2.12.1, BA.4 and BA.5, that are currently in circulation are more transmissible than the original Omicron strains of BA.1 and BA.2, finds a new study published in the medical journal Nature.

This means that those infected with Omicron in the early days of the variant are unlikely to be protected against these newer subvariants.

This may explain the sudden rise in COVID cases that we are seeing once again in various parts of the world where these subvariants have been detected.

On 20 June, India reported 12,781 new COVID cases in 24 hours. This is the fourth consecutive day the country has reported over twelve thousand daily cases.

Key Points From the Study

Subvariants BA.2.12.1, BA.4 and BA.5, "notably evade the neutralizing antibodies elicited by SARS-CoV-2 infection and vaccination," said the study authors.

The peer-reviewed study conducted by researchers at Peking University, China, tested blood samples from participants that received,

• 3 doses of the COVID vaccine

• 2 doses of the COVID vaccine and were previously infected with BA.1

The study found:

• BA.2.12.1 and BA.4/BA.5 are able to circumvent the plasma from 3-dose vaccination better than BA.2.

• The risk of reinfection with BA.4/Ba.5 remains high in those who have been vaccinated and then infected with BA.1

The study also found that Omicron-targetted vaccines, like the ones being developed by Moderna and Pfizer-BioNTech, "may not achieve broad-spectrum protection against new Omicron variants."

Interestingly, the researchers also found that the monoclonal antibody treatments, Bebtelovimab and Cilgavimab, could neutralize BA.2.12.1 and BA.4/BA.5 post infection.

Infections Vs Illness

Previous research, and real world data also suggest that the newer Omicron variants are more transmissible than the previous ones.

Although the newer subvariansts have been found to be more transmissible, and capable of circumventing vaccine protection and past infection, there isn't enough evidence to suggest they cause more severe illness yet.

Experts that FIT has spoken to for another article in the last few weeks have reiterated the importance of making a distinction between infections and illnesses.

"It is impossible to stop the infection of a virus that is as infectious as SARS COV2," says Dr Vineeta Bal, Immunologist, and researcher at the Indian Institute of Science Education and Research (IISER Pune).

"But once it gets in, whatever immunity we have as T cells, B cells, antibodies, all of it comes together so that further spread – which is responsible for illness – is decreased."

Dr Vineeta Bal

There is no considerable threat of severe illnesses going up unless a new variant emerges that turns out to be more virulant, added Dr Satyajit Rath, Immunologist, National Institute of Immunology, speaking to FIT at the time.