[ad_1]
Last week, Novavax released the results of its COVID-19 vaccine trials that are raising concerns in the United States as new, more transmissible – and possibly more deadly – variants emerge. In Britain, where a more transmissible strain known as s B.1.1.7 is the dominant strain, the two-dose vaccine had an effectiveness rate of almost 89.4 percent. But in South Africa, where the B.1.351 strain primarily circulates, the efficacy rate has fallen to 50 percent.
Johnson and Johson’s clinical trial data yielded similar results. The company’s single-injection vaccine was 66% effective in a large-scale trial that spanned three continents. In the United States, the effectiveness of the vaccine has reached 72%. In South Africa it was 57%.
While headlines communicating the news of reduced effectiveness may sound alarming, epidemiologists say it is not yet time to panic. In the world of vaccines, 50% efficacy is still impressive.
“The flu vaccine is 36 percent effective,” said Dr. George Rutherford, professor of epidemiology at the University of California, San Francisco. “The fact that we set the bar at 95 is just phenomenal; and it’s the best vaccine we have, which is the measles vaccine.”
Moderna and Pfizer vaccines also account for over 90%.
Rutherford said the news regarding the protection of the Johnson & Johnson and Novavax vaccines against the new variant is “very encouraging”.
“It’s solid protection,” Rutherford said.
Amesh Adalja, senior researcher at the Johns Hopkins Center for Health Security, agreed.
“You have to remember that this 50 percent figure reflects its effectiveness in preventing symptomatic illnesses, so it’s not the same as serious illness, death, and hospitalization, where they’re very effective,” Adalja said. “So the good story of the Novavax vaccine is that even in the face of the South African variant, the Novavax vaccine prevents serious illness from COVID-19, prevents deaths from COVID-19, prevents hospitalization of COVID-19 . “
As the World Health Organization explains, vaccine efficacy is the percentage of “reduction in the incidence of disease in a vaccinated group compared to an unvaccinated group under optimal conditions.” This should not be confused with the efficacy of the vaccine, which is the ‘ability of the vaccine[s] to prevent interesting results in the “real world”. “
Experts warned in the BMJ that comparing the lowest to highest efficacy rate is a “mistake,” especially given that Johnson & Johnson is set to be a game-changer in the international rollout of the vaccine. Unlike Moderna, Pfizer and Novavax vaccines, which both require injections, Johnson & Johnson only require one. It also has lower storage requirements which make it more flexible to store and administer.
“The real headline result is that a single-injection vaccine, capable of easy long-term storage and administration, provided complete protection against hospitalization and death,” said Kevin Marsh, professor of medicine. tropical at the University of Oxford, BMJ. “This is important because the immediate need for vaccination around the world is to limit deaths as quickly as possible.”
The B.1.351 variant first appeared in Durban, South Africa. Scientists have been alarmed that the virus mutation is at the peak level of SARS-CoV-2, obscuring its appearance to the immune system, which can make it easier to bypass immune protection. This is why scientists are seeing a decrease in the effectiveness of the vaccine, which they believe would be the case from the start.
There is cause for concern that the coronavirus is mutating where it is found. Yet any ineffective vaccine will help stop the spread of the coronavirus. This will have a domino effect, as lower transmission means less virus replicating, and therefore mutant.
“Viruses cannot mutate if they cannot replicate themselves,” Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Monday. “If you stop their replication by vaccinating extensively … not only will you be protecting people against disease, but you will also be preventing the development of variants.”
Adalja told Salon that the goal at the moment is not to eradicate the coronavirus, but rather to reduce the serious consequences.
“We are not getting rid of this, it will not be eradicated like smallpox,” he said. “What we’re trying to do is sort out this virus, make it something that’s more like the other coronaviruses that cause 25% of our common colds by giving people immunity through a vaccine … that’s what these vaccines do, people are forgetting that the end game here is to avoid death. “
But what if new variants emerge and become smart enough to completely outsmart our vaccines? Well, then the scientists will have to modify the vaccines. Adalja said it was “not clear” at this point if this is something we will need to do in the future, but if we do, it is relatively “easy to do”.
“Novavax uses a recombinant platform, which is very easy to modify,” Adalja said.
Rutherford said vaccines may need to be changed “as this virus evolves”. Still, he is encouraged by the news, especially by what has caught on in the Israeli press. A man who had previously recovered from COVID-19 was re-infected with the B.1.351 strain, but the second time around he had very few symptoms.
“Naturally acquired immunity appears to have some level of protection against serious illness, which we are trying to do,” Rutherford said.
[ad_2]
Source link