During the first wave of vaccine rollout, people were optimistic about the pandemic’s end. Many believed that reaching herd immunity through vaccination would help us transition back to our normal lives without masks and physical distancing.
But the emergence of COVID-19 variants cast some doubts on vaccine efficacy. We’ve heard about how Delta, Lambda, and Omicron could evade immunity. Then, there were scares about Deltacron and IHU variants. This has gotten some people asking: Do we need to reimmunize whenever a new variant of COVID-19 appears?
The COVID-19 Virus May Follow The Pattern Of The Common Cold
The head of the Immunology Department at the Research Institute for Tropical Medicine (RITM), Dr. Mario Jiz, mentioned that we might need to reimmunize or re-boost the public each time a new variant of concern emerges.
But, before expounding on that, the doctor first talked about patterns within coronaviruses.
Remember that SARS-CoV-2 comes from a large family of viruses, Coronaviruses, which cause mild (common cold) to severe respiratory diseases (SARS).
With the common cold, notice that our immunity diminishes after some time. That’s why some adults have colds twice or thrice a year. Dr. Jiz stated that if the COVID-19 follows this pattern, then our immunity against it also wanes in that period. This could mean that a year, a year and a half, may be the efficacy period of our vaccines¹.
Reimmunization Whenever There Is A Concerning New Variant Of COVID-19, Possible According To An Expert
Dr. Jiz also mentioned that just like the flu, we might need to have variant-specific immunizations.
He hopes we wouldn’t have to do it yearly, but he said we might have to check if current vaccines would still work for the new variants of concern. After all, the existing vaccines were meant for the original SARS-CoV-2 discovered in Wuhan, China late in 2019.
The need for reimmunization likewise increases if the new variant of COVID-19 has many mutations since the chance of it evading immunity is higher.
For Now, What We’re Doing Is Enough
Despite the possibility of reimmunization whenever there’s a concerning new variant of COVID-19, Dr. Jiz said what we’re doing now is sufficient.
If we’re healthy (no comorbidities) and relatively young (less than 60), then getting the primary and booster is enough, even if new variants appear. “As long as the variant doesn’t have too many mutations,” the doctor added.
How The Vaccines Are Doing Against The Variants
At this point, you must be curious: How are the vaccines doing against the variants we have now, particularly the feared Delta and now-dominant Omicron?
First, a Danish study involving vaccinated individuals noted that Omicron is more transmissible than Delta. That means Omicron is better at evading immunity provided by the vaccines than its predecessor. The good news is that Omicron appears to cause less serious symptoms and those who are booster-vaccinated are less likely to transmit COVID-19 regardless of the variant².
Another report concluded that the vaccine effectiveness of 3 doses of Moderna vaccine (mRNA-1273) was “high and durable” against Delta, but lower with Omicron. The vaccine effectiveness is especially lower for immunocompromised patients3. The report added that no patient who received 3 doses of Moderna was hospitalized for COVID-19³.
A CDC report also said that 3 doses of mRNA vaccine were highly effective at preventing COVID-19-related emergency and urgent care encounters as well as hospitalization. This conclusion is true for both Delta and Omicron variants⁴.
The Implications
Do we need to reimmunize whenever there’s a new variant of COVID-19? An expert says we might, especially if the variant has too many mutations capable of escaping immunity.
For now, getting your primary dose and booster shot is sufficient. If you’re still worried about COVID-19 vaccines, please don’t hesitate to get in touch with your doctor.
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