Al Jazeera English News interview - 17 Apr 2021: new virus variants and vaccine

We’d like your views about the new coronavirus variants, 

According to the US CDC's classification scheme for variants of SARS-CoV-2, there are 3 categories:

variants of interest, variants of concern and variants of high consequence

Currently CDC listed 3 for variants of interest, 5 for variants of concern and none for variants of consequence.

What are the attributes of a variant of concern:

There are evidences of impact on diagnostics, treatments and vaccines, increased transmissibility or increased disease severity. On the vaccines, we are concerned with the possibility of reduced vaccine-induced protection and efficacy.

Each of these variants has a number of mutations, and some of these are key mutations in critical regions of the viral genome. Because the spike protein is required for the virus to attach to human cells, it carries a number of these key mutations. In addition, antibodies that neutralize the virus typically bind to the spike protein, thus making the spike sequence or protein a key component of COVID-19 vaccines.

 

how concerned public health experts are, 

The 3 variants of concern circulating in the wider world are: the B.1.1.7, which originated in the U.K (now found in 108 countries).; the B.1.351., of South African origin (found in 69 countries); the P.1., first seen in Brazil (found in 35 countries).

Several reasons why we should worry about these variants. 

First, the variants of concern generally transmit from person to person at least 20 to 50% more easily. This makes them infect more people in a shorter time hence spread more quickly and widely, eventually becoming the predominant strain.

For example, the B.1.1.7 U.K. variant has raked up more than a quarter of all cases by mid-March, in about just 3 months after the first detection. The P1 variant that emerged in Brazil killed at least 60,000 deaths in Brazil just in the month of March.

So, at this point, we also concern that the new variants could lead to more severe disease and increased hospitalizations and deaths. Recent publications in Nature and BMJ showed that the B.1.1.7 variant causes more severe illness and mortality in the UK.

Our next concern is whether these new variants can escape the immunity elicited by natural infection or vaccination-induced effort. We are worried that antibodies from recovered patients or vaccinated persons may not be able to bind as efficiently to a new variant virus, and this could lead to reinfections and lower the effectiveness of current treatments and vaccines.

what impact this could have on vaccination drive and herd immunity goals.

The current data, though limited, but worrying. For example, AstraZeneca vaccine-induced antibody response when they meet with the new variant from South Africa, it can get weakened up to a factor of 86 times until complete immune evasion. Vaccine efficacy also plunged from 66% against the first Wuhan variant to just 22% against the South Africa new variant. Moderna and Pfizer's vaccines also have their induced-antibody neutralization activity attenuated up to a factor of 8.6 times.

However, another study shows that the T-cell immune responses, either elicited by natural infection or vaccination, can recognise all three UK, South Africa and Brazil variants. That means there will still be some degree of protection conferred by vaccination against such variants.

In a recent survey of global epidemiologists general consensus, the majority of them believed that within a year current vaccines could need to be updated to better handle new variants, and that low vaccine coverage will likely facilitate the emergence of such variants. We should assume the current SARS-CoV-2 variants will likely continue to evolve and adapt. Vaccine researchers and manufacturers would have to include some other more constant region of virus as vaccine targets, other than spike protein, for example, nucleocapsid protein.

So, what is important for the general society and government to do is to keep the disease transmission low and vaccinate as many people in as many places as soon as possible to reduce the number of cases and the possibility for the virus to incubate and generate new and potent variants which can further evade immune responses. Currently, we have to address the vaccine hesitancy issue in this country and ensure the global vaccine supply is equitable and timely accessed for everyone.