MercoPress. South Atlantic News Agency

WHO warns vaccines have yet to prove that they are effective at preventing Covid-19 transmission

The vaccines have been found in large trials to prevent recipients from becoming sick or seriously ill, but researchers have not determined whether the vaccines prevent the virus from spreading

Officials at the World Health Organization warned that the COVID-19 pandemic that has ravaged every corner of the world “is not necessarily the big one” — and that the novel coronavirus may never truly go away.

What’s more, chief scientist Dr. Soumya Swaminathan said the WHO hasn’t yet determined whether the approved vaccines being administered in Canada, the U.S. and Europe are effective at preventing transmission.

“I don’t believe we have the evidence on any of the vaccines to be confident that it’s going to prevent people from actually getting the infection and therefore being able to pass it on,” Swaminathan said.

The top three vaccines — Moderna, Pfizer-BioNTech and AstraZeneca — have been found in large trials to prevent recipients from becoming sick or seriously ill, but researchers are still trying to determine whether the vaccines prevent the virus from spreading from the recipient to others.

Even if people have received the vaccine, countries still need to assume that they should adhere to public health measures such as social distancing. If a vaccine recipient wants to travel, he should still be required to quarantine.

Moderna’s chief medical officer said last month he believes his company’s vaccine would prevent transmission of the virus but there is not yet “sufficient evidence” of that yet.

“When we start the deployment of this vaccine we will not have sufficient concrete data to prove that this vaccine reduces transmission,” Tal Zaks told Axios.

The first goal of the vaccine was meant to prevent symptomatic disease, severe disease and deaths, Swaminathan said.

Dr. Mark Ryan, the head of the WHO emergencies program, said after that first goal has been tackled, “we will deal with the moon shot of potentially being able to eliminate or eradicate the virus.”

Ryan said, “The existence of a vaccine, even at high efficacy, is no guarantee of eliminating or eradicating an infectious disease. That is a very high bar for us to be able to get over.”

Instead, the “destiny” of the virus is to become endemic, said David Heymann, the chair of the WHO’s strategic and technical advisory group for infectious hazards.

Heymann said the world hoped for herd immunity but the concept of herd immunity was misunderstood. Like other human coronaviruses, COVID-19 will continue to mutate and reproduce in human cells.

“This pandemic has been very severe … it has affected every corner of this planet. But this is not necessarily the big one,” Ryan said. However, if there’s one thing 2020 provided the world with, it’s perspective and lessons learned.

“This is a wake-up call. We are learning, now, how to do things better: science, logistics, training and governance, how to communicate better. But the planet is fragile,” said Ryan.