The emergence of nCoV variants in South Africa and Brazil has made scientists worried and cautious when predicting the development of Covid-19.
Chris Murray, an epidemic specialist at the University of Washington, is behind the world-trusted pandemic predictor models. Recently, he expressed his hope that natural immunity and vaccines will help humanity achieve community immunity and repel Covid-19. However, in February 2020, data from a vaccine trial in South Africa showed that the new virus variant not only reduced the effectiveness of the vaccine, but also caused many people to re-infect.
“I was unable to sleep after looking at the figures,” Mr. Murray said. Currently, he is still updating the system to explain the ability of the virus to evade the immune system and will make a new prediction soon.
18 experts are watching and trying to contain the disease, saying that highly effective vaccines bring a spark of hope. In November 2020, pharmaceutical companies Pfizer and BioNTech as well as Moderna announced their vaccines were about 95% effective in preventing Covid-19, much higher than any flu vaccine. Prior to this information, some scientists said they did not expect the vaccine to stop the virus. Conversely, many say they hope the pandemic will end if the world develops the vaccine fast enough. “We were all quite optimistic before Christmas because of the products. They were highly effective despite being the first generation of vaccines,” said Azra Ghani, head of epidemiology at Imperial College London. .
However, the joy is short-lived. In late December 2020, the UK issued a warning about a new, more contagious nCoV variant that is rapidly gaining popularity in the country. Around the same time, the researchers learned about the effects of variations in South Africa and in Brazil.
In November 2020, Phil Dormitzer, a leading scientist at Pfizer, considered the Covid-19 vaccine “a breakthrough for mankind”. But in early January, he admitted the nCoV variants marked a new chapter in the fight against the campaign. Pharmaceutical companies will have to continuously monitor for mutations that may impair the effectiveness of the vaccine.
Facing unpredictable developments of the epidemic, experts recommend that people continue to observe measures such as wearing masks and avoiding crowded places. Dr. Anthony Fauci, President Joe Biden’s chief medical advisor, said he still wears a mask despite being vaccinated.
From the very beginning, nCoV was a difficult target to destroy. At the beginning of the pandemic, leading scientists, including Dr. Michael Ryan, head of the World Health Organization’s emergency program, warned “nCoV may never go away”.
Murray said that if the South African variant or similar variants continue to spread rapidly, the number of Covid-19 hospitalizations or deaths in the US next winter could be four times higher than the number hospitalized. or die from the flu. This estimate comes into the context of the assumption that half of the US population that is vaccinated is 65% effective.
His current forecast as of June 1 states that there will be an additional 62,000 deaths in the US and 690,000 more deaths globally from Covid-19. The model includes calculations of vaccination rates as well as potential spread of the South African and Brazilian variants.
The change in scientific perception has made governments also more cautious. The UK recently announced that it will slowly lift the blockade, despite being one of the fastest immunization rates.
American predictions for a return to normal life have been repeatedly pushed back, from late summer to Christmas, and then March 2022. Israel issues green cards to people who have left Covid-19 or have been vaccinated, allowing them to return to hotels or theaters. However, this card is only valid for 6 months as it is not clear how long the immunity will last.
Some scientists, including Murray, admit the future is still promising. New vaccines are being developed at record speeds, seemingly still helping prevent the risk of hospitalization and death, even when infected with the new variant. Many manufacturers are working on booster shots and new highly effective vaccines against variants. Besides, scientists still believe that there is still much to learn about the anti-virus capabilities of the immune system.
Mai Dung (Follow Reuters)