Variants Fuel Covid-19 Surge, but scientists express optimism for vaccines

Scientists say variants can be brought under control with known health measures such as wearing a mask and social distance, despite evidence that some strains may evade the immune response caused by vaccination or an infection in the past.

In the UK, for example, where a variant known as B.1.1.7 caused a deadly new outbreak in winter, new cases have dropped to a drop after a strict lock-up and rapid vaccination.

Scientists are also hopeful that the current crop of vaccines will at least limit the number of people who become seriously ill and die from Covid-19, even if the variant weakens the effectiveness of the vaccines to prevent infection. Vaccines are already testing new versions of their shots that have been re-adapted to attack variants.

Progress, however, depends on the downfall of business, both to save lives and to limit the opportunities of the virus to provoke even more beneficial mutations that could propel future waves of infection.

“The chances of winning the lottery are very small – until you buy 65 million lottery tickets,” said David Bauer. He leads a group at the Francis Crick Institute in London and studies how coronavirus mutations affect the transmission and severity of diseases. “That’s why you have people who are virologists who say that what we really need is to lower the infection rate.”

According to the World Health Organization, the new Covid-19 cases rose worldwide for the seventh consecutive week in the seven days to Sunday, with cases in Southeast Asia being 63% higher than the previous week, fueled by a growing epidemic in India. Other hotspots include Turkey, where cases were a third higher, and parts of the Americas and Europe. Infections increased by 5% in the US and by 9% in France.

Several versions of the virus – the result of small errors during replication – have emerged since it appeared in China at the end of 2019. Mutations that give the virus an advantage will tend to continue and accumulate, eventually giving rise to clear virus lines with subtly different characteristics from their predecessors.

Two of these variants now promote a significant portion of the current wave of infection, followed by countries with the ability to sequence viral genomes.

Much of Latin America was involved in an aggressive variant known as P.1, which originated in early November last year in the city of Manaus in the Amazon in Brazil. The variant has now been detected in at least 36 countries and in 22 US states.

In Brazil, where about 130 people die from Covid-19 every hour, P.1 has become the dominant tribe. A study this month shows that P.1 is responsible for more than 90% of new infections in São Paulo, the largest city in the Southern Hemisphere.

In Canada, the British Coast province of British Columbia became one of the largest P.1 hotspots outside Brazil, forcing local authorities to ban food and religious services until at least April 19 and the popular Whistler Blackcomb ski resort north of Vancouver.

Canada is also plagued by the B.1.1.7 variant, which was first isolated and described in Kent, England at the end of last year. It has since spread to 114 countries and, according to the Centers for Disease Control and Prevention, and in large parts of Europe, is now the dominant version of coronavirus spread in the US.

In Ontario, Canada’s most populous region, about two-thirds of all new Covid-19 cases are involved in B.1.1.7, which results in health care systems.

‘We are already in a situation where it is no longer the vaccines against the variants. This is the variant versus the ICU capacity, ”said Amit Arya, a palliative care physician in the greater Toronto area and professor at McMaster University in Hamilton, Ontario.

In Spain, the health authorities said that this variant was responsible for between 64% and 99% of the new infections observed in 17 Spanish regions last week, while the health authorities in Italy said at the end of March that the British variant 87% of the new cases represented there.

A third variant that worries scientists is B.1.351, which was first detected in South Africa at the end of 2020. It spreads rapidly across the continent’s most developed economies and nearby countries, including Zimbabwe, Mozambique and Zambia.

B.1.351 has since been detected in nearly 70 countries, including the US, although it has not become a major source of infections outside of Southern Africa. In the US, the CDC says that B.1.351 in the second half of March was responsible for about 0.7% of the Covid-19 cases, while about 1.4% of the cases by the P.1 strain from Brazil caused. B.1.1.7 was the source of approximately 44% of the infections.

The three variants are worrying for several reasons. All three share a mutation that scientists nicknamed Nelly – a play about the alphanumeric name N501Y – which appears to increase transmissibility. Studies have suggested that the British variant, for example, is between 43% and 90% more transmissible than the original virus, with similar or greater increases in contagion for the South African and Brazilian variants.

Doctors are concerned that the new variant could lead to serious illnesses or increase the risk of death in someone infected. Doctors and hospital directors across Brazil have said in interviews with The Wall Street Journal that they suspect P.1 is more deadly, noting an increase in younger and otherwise healthier patients being admitted to ICUs. However, studies examining the mortality risk associated with each variant have sometimes come to different conclusions. Scientists say to make sure solid evidence is needed.

Another question mark depends on how well the vaccines will be rolled out around the world in places where these variants are circulating and dominant, and whether these variants will be able to seed new outbreaks, even in places where the vaccination is widespread.

South Africa has decided not to use vaccines developed by the University of Oxford with AstraZeneca PLC and by Novavax Inc.

after relatively small clinical trials, it showed reduced efficacy compared to B.1.351. The country is rather working on the shots developed by Johnson & Johnson and by Pfizer Inc.

with BioNTech SE.

Several laboratory studies worldwide paint a broad picture of vaccines that work adequately against the UK and Brazilian variants, but less well against the variant first observed in South Africa.

Scientists say that these studies do not necessarily tell the whole story, as the immune responses generated by a vaccine in the body are wider and deeper than those that can be easily observed in a laboratory. Although existing vaccines are not as effective at preventing new variant infections as against older strains, they should probably work well enough to prevent most people from becoming seriously ill, said David Matthews, a virologist at the University of Bristol. England, said. .

“If the vaccines can keep people out of the hospital, it does not matter if you catch a cold for a few days,” said Dr. Matthews said.

Vaccine manufacturers are working on shots that target these variants more precisely and can be distributed as shot shots if necessary.

“Vaccine technology can change very quickly,” said Ewan Harrison, a microbiologist at the Wellcome Sanger Institute, a biomedical research center. “If I really wanted to put my money where my mouth was, I would say that in the coming years there will be a risk of populations with dual flu and Covid vaccines.”

—Paul Vieira, Luciana Magalhaes, and Giovanni Legorano contributed to this article.

Write to Jason Douglas at [email protected], Gabriele Steinhauser at [email protected] and Samantha Pearson at [email protected]