In a bit of encouraging news as the coronavirus rages through the US and elsewhere, World Health Organization (WHO) scientists said currently approved vaccines should work well on new variants of the SARS-CoV-2 virus that causes COVID-19.
The variants are worrisome because they may propagate faster but they “do not seem to cause more severe illness or a higher death rate or any sort of different clinical manifestations,” WHO’s chief scientist Soumya Swaminathan said.
The novel coronavirus has gone through many changes since early 2020. Now, two particular variants have been reported to WHO, identified in Britain and South Africa.
The variants have one change in common, called the N501Y mutation. The reason for concern is that both of these variants were associated with an increase in the number of cases in both countries.
Scientists report that these two variants tend to spread faster and are more transmissible or more infectious. Apart from that, they seem to behave like the previous viruses and cause a similar kind of disease.
It is very important that vaccine developers keep in mind the changing nature of the coronavirus. For instance, some vaccines like measles do not need to be changed at all because the vaccine works well all the time. But the structure of some vaccines, like those against the influenza virus, have to be changed every year, based on the circulating strains. WHO coordinates the global network that actually identifies which strain should be used every year.
For SARS-CoV-2, practitioners are still learning and knowledge is evolving. “At this point in time, most scientists believe that the vaccines that are currently in development and a couple that have been approved should provide protection against this variant and other variants because these vaccines elicit a fairly broad immune response, a host of antibodies and cell-mediated immune responses,” she noted.
So, a few changes or mutations in the virus should not make these vaccines ineffective. However, studies are continuing in labs around the world to confirm this.
In the small possibility that the vaccines are less effective against one or both of these variants, it will be possible to change the composition of the antigens and the vaccines quite quickly.
“What we know about this variant and previous variants is that the virus is still behaving in the same way. It is spreading in the same way. And the more we give it a chance to spread and to multiply within humans, the more chances it is going to have to keep changing itself. That is its natural property,” she explained
Therefore, the focus everywhere should be on ensuring that everything is being done to reduce transmission. This is possible because the things that work are well known. They include identifying those who are infectious; providing them with supportive isolation; tracking and contact tracing; quarantining all the contacts; and making sure that people continue to comply with physical distancing, wearing a mask and avoiding crowded places. It is also necessary to avoid closed settings where there are a lot of people; and observe practices like washing hands, respiratory etiquette, staying home if you are sick.
All of these things together certainly make a difference in bringing down transmission. This has been proven repeatedly in country after country. It is time to double down because the same public health and social measures will work against these variants, as have worked in the past.
“Right now we’re at a very critical stage in many parts of the world, where we really need to be focusing on bringing down the transmission and that in turn will help in reducing how much this virus can actually change,” Swaminathan insisted.
Another WHO epidemiologist Maria Van Kerkhove said that those who recover from COVID-19 may not have lifelong immunity so they should still observe public health measures wherever they live.
When individuals are infected with the SARS-CoV-2 virus, they develop antibodies a few weeks after infection whether they have severe disease, mild disease, or asymptomatic infection. Studies are underway to assess how strong this immune response is and for how long these antibodies last. Although there is no clear picture yet, it is possible that those who recover from COVID-19, can get reinfected.
“What we understand is that there are individuals that can be reinfected with this virus, as is common with other viruses,” she added. “We do not know how often this is happening, but we have a number of instances from countries that have reported reinfection of individuals because they have good lab systems and they’re able to do full genome sequencing of the first infection and the subsequent infection.”
“There’s still so much, we need to understand about occurrences of re-infection, how often it is happening and what it means for the individual patient. Is the second infection more severe or less severe? And what does it mean in terms of the antibody response?” she pointed out.