COVID-19 disease is caused by a SARS-CoV-2 virus, which is now carefully researched by scientists all across the globe. Scientists at UCL say that the next generation vaccines for Covid-19 should target ‘replication proteins’, which constitute the early stages of the viral cycle. This could eliminate the virus before it could start to replicate, providing better protection from the most difficult cases of the disease.
SARS-CoV-2 virus, which causes COVID-19 disease. Scientists are still looking for its weak spots to attack with the new generation of vaccines. Image credit: NIAID via Wikimedia (CC BY 2.0)
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Naturally, COVID-19 vaccine development has been in the spotlight for some time now and you’ve heard about scientists trying to target spike proteins, situated at the surface of SARS-CoV-2 virus. Current vaccines are aiming at those proteins and are fairly effective at preventing the most difficult consequences of the infection. However, scientists believe that the next generation of COVID-19 vaccines could have a wide mode of attack – antibodies could target the spike protein, while memory T cells could launch an attack against replication proteins.
Replication proteins are required for the earliest stage of the virus’s life cycle. As soon as SARS-CoV-2 virus enters a cell it needs to start replicating to spread the infection. Replicating protein takes care of that and spike proteins only appear slightly later in the virus development. Importantly, replication proteins do not change too much with mutations – scientists describe them as ‘highly conserved’. Furthermore, these replicating proteins are not unique to SARS-CoV-2 virus, which means that the new generation of vaccines would not only provide protection against SARS-CoV-2 and its variants, but also against coronaviruses that cause common colds and other coronaviruses in the future.
Scientists started the hunt for SARS-CoV-2 replication protein by investigating healthcare workers who showed no sign of SARS-CoV-2 infection even during the very start of the first UK pandemic wave. Scientists found that a subset of healthcare workers appear to have experienced a transient low-level infection, which was so mild that it was undetectable using PCR and antibody tests. However, this infection, as this study showed, was enough to develop specific T cells targeting replicating proteins.
Dr Leo Swadling, lead author of the study, commented: “By intensively monitoring health care workers for signs of infection and immune responses, we identified a minority with this particular SARS-CoV-2 specific T cell response. What is really informative is that the T cells detected in these individuals, where the virus failed to establish a successful infection, preferentially target different regions of the virus to those seen after infection.”
Vaccines are probably the only way of coming out of COVID-19 pandemic. Current vaccines are fairly effective, but they could be better in the future stopping the infection even earlier and preventing tragic consequences even more effectively.
Source: UCL