At least that mutation doesn't appear to be a problem
No início de 2021, enquanto novas variantes do coronavírus desafiavam os esforços globais de vacinação, um estudo preliminar trouxe uma nota de esperança cautelosa: a vacina da Pfizer parecia capaz de resistir à mutação N501Y, partilhada pelas variantes do Reino Unido e da África do Sul. A ciência, ainda a aguardar revisão por pares, lembrava-nos que a corrida entre o vírus e o engenho humano é antiga — e que as ferramentas já construídas podem, por vezes, resistir ao que ainda está por vir.
- A descoberta de variantes mais contagiosas no Reino Unido e na África do Sul intensificou o receio de que as vacinas já aprovadas pudessem tornar-se ineficazes antes de chegarem à maioria da população.
- Investigadores da Pfizer e da Universidade do Texas testaram anticorpos de vinte vacinados e confirmaram que estes neutralizaram com sucesso as variantes portadoras da mutação N501Y em ambiente laboratorial.
- A vacina mostrou eficácia contra cerca de quinze mutações possíveis, mas a variante E484K, presente na África do Sul, permanece por testar — uma lacuna que mantém os cientistas em alerta.
- O responsável científico da Pfizer garantiu que, se necessário, a vacina poderia ser reformulada com relativa rapidez, à semelhança do que acontece anualmente com as vacinas contra a gripe.
- Com quase 1,88 milhões de mortos e mais de 87 milhões de infetados em todo o mundo, os resultados preliminares surgem como um sinal encorajador — mas a confirmação real-world ainda está por chegar.
Em janeiro de 2021, quando novas variantes do coronavírus começaram a alarmar cientistas e governos, um estudo preliminar da Pfizer e da Universidade do Texas veio oferecer algum alívio. Ainda sem revisão por pares, a investigação sugeria que a vacina da Pfizer-BioNTech mantinha a sua eficácia contra a mutação N501Y — a alteração partilhada pelas variantes identificadas no Reino Unido e na África do Sul, e que tornava o vírus significativamente mais transmissível.
A questão central era simples e urgente: as vacinas, concebidas para ensinar o sistema imunitário a reconhecer a proteína de superfície do vírus, continuariam a funcionar se essa proteína tivesse mudado? Para responder, os investigadores analisaram amostras de sangue de vinte pessoas vacinadas e expuseram os seus anticorpos às novas variantes em laboratório. Os resultados foram positivos — os anticorpos neutralizaram o vírus com sucesso.
Philip Dormitzer, diretor científico da Pfizer, descreveu os dados como encorajadores, sublinhando que a mutação mais temida não parecia comprometer a proteção conferida pela vacina. A vacina demonstrou eficácia contra cerca de quinze mutações possíveis. Ainda assim, a variante E484K, detetada na África do Sul, não havia sido testada — uma incógnita que os cientistas reconheciam abertamente.
Dormitzer acrescentou que, caso o vírus evoluísse de forma mais drástica, a vacina poderia ser atualizada com relativa facilidade, seguindo um modelo semelhante ao das vacinas anuais contra a gripe. A infraestrutura e o conhecimento já existiam. Num mundo com quase dois milhões de mortos e dezenas de milhões de infetados, esta evidência laboratorial não era uma vitória — mas era, pelo menos, uma razão para não desistir das ferramentas já em mãos.
In early January 2021, as new variants of the coronavirus began spreading across the globe, a preliminary study offered a measure of reassurance: Pfizer's vaccine appeared capable of protecting against the mutations that made these strains so worrisome. The research, conducted by scientists at Pfizer and the University of Texas, had not yet undergone peer review—a critical step in validating scientific findings—but the initial results suggested the vaccine could hold up against at least some of the virus's most troubling changes.
The variants emerging from the United Kingdom and South Africa shared a common mutation called N501Y, a small but significant alteration in the protein that coats the virus's surface. This change made the virus more transmissible, and it raised an urgent question: would existing vaccines still work? Most of the vaccines being rolled out worldwide were designed to train the immune system to recognize and attack that very protein. If the mutation rendered it unrecognizable, the vaccines could lose their power.
To test this possibility, researchers examined blood samples from twenty people who had received the Pfizer-BioNTech vaccine. In laboratory conditions, they exposed the antibodies in those samples to the new variants carrying the N501Y mutation. The antibodies held their ground. They successfully neutralized the virus in the test tube, suggesting that vaccinated people would likely retain protection against these new strains.
Philip Dormitzer, Pfizer's chief scientific officer, described the findings as encouraging. "At least that mutation, which is one of the ones people worry about most, doesn't appear to be a problem," he said. The study indicated the vaccine could work against roughly fifteen possible viral mutations. But there was a caveat: another mutation called E484K, which had been detected in the South African variant, had not yet been tested in the laboratory.
Dormitzer acknowledged that if the virus underwent major evolutionary changes, the vaccine would eventually need adjustment—much like the annual reformulation of flu shots. But he emphasized that such modifications would not be difficult for Pfizer or other vaccine manufacturers to implement. The infrastructure and expertise already existed. If needed, the vaccine could be updated relatively quickly.
At the time of the study's release, the pandemic had claimed at least 1.88 million lives worldwide, with more than 87 million confirmed infections across every continent. The virus itself, first identified in Wuhan, China, in late December 2019, had reshaped the world in just over a year. The emergence of these new variants had deepened the anxiety surrounding the pandemic's trajectory. But this early laboratory evidence suggested that the scientific tools already in hand might not become obsolete overnight. The question now was whether real-world protection would match what the test tubes showed.
Citações Notáveis
At least that mutation, which is one of the ones people worry about most, doesn't appear to be a problem— Philip Dormitzer, Pfizer chief scientific officer
If the virus undergoes major mutations, vaccine adjustments would be feasible, similar to annual flu shots— Philip Dormitzer, Pfizer
A Conversa do Hearth Outra perspectiva sobre a história
Why does this particular mutation matter so much? There are thousands of mutations in any virus.
The N501Y mutation changes how the virus grabs onto human cells. It makes the virus stickier, more efficient at infecting people. That's why these variants spread faster. If the vaccine couldn't recognize it, vaccination rates wouldn't matter—the virus would still find its way through.
So the fact that antibodies from vaccinated people still neutralized it in the lab—that's the real news here?
Yes. It's preliminary, and it's in a test tube, not in a person's body. But it's the first signal that we might not be starting from zero with each new variant. The vaccine isn't obsolete yet.
What about that E484K mutation they didn't test?
That's the honest part of the story. They tested what they could with the time they had. E484K was in the South African variant but hadn't been as thoroughly studied yet. It's a gap they knew existed.
If the virus keeps mutating, does that mean we're chasing it forever?
Possibly. But Dormitzer's point about flu vaccines is important. We've been doing this for decades with influenza. We don't remake the vaccine from scratch each year. We adjust it. If COVID becomes like that—a virus we update against annually—that's manageable. It's not ideal, but it's not catastrophic either.
Twenty people is a very small sample.
It is. That's why peer review matters. Other scientists need to replicate this, test more samples, test in real people. This study is a beginning, not an ending.