At a record speed, vaccines are here and there are many more on the way. Less than a year since the coronavirus began ravaging the world, the first shots are raising hopes of clearing the Covid-19 pandemic from the earth’s surface.
Current programs in the United States and the United Kingdom are forerunners of vaccination campaigns aimed at reaching the entire population of the planet, the 8 billion people in every corner of the globe.
There are reasons for optimism. Vaccines are the best and perhaps the only way to eliminate infectious diseases: smallpox has been eradicated and polio is on the verge, with only two countries where transmission persists. But global vaccination campaigns take time (usually decades), suggesting that even with the latest technology, money, and power behind the unprecedented global push to eliminate Covid-19, it is the disease is unlikely to be eradicated soon.
“I would be surprised to see a real eradication of this virus now that it’s worldwide,” said Walter Orenstein, associate director of the Emory Vaccine Center in Atlanta and former head of the Centers for Disease Control and Prevention’s immunization program. of the United States. “I would be surprised, given how contagious it is.”
Supply and distribution problems already arose in the early days of the US campaign, and the UK, the first Western country to start vaccinating itself, vaccinated only 138,000 people in the first week. Meanwhile, Europe has not yet begun to inoculate itself and will probably not do so until after Christmas.
Concerns are growing about how long it will take to immunize vast swathes of the world beyond a group of rich countries that have secured early supplies. A global program called Covax, which aims to deploy Covid vaccines around the world, has reached agreements with developers such as Johnson & Johnson and AstraZeneca Plc. But some of those supplies are expected to come from an experimental inoculation of Sanofi and GlaxoSmithKline Plc that has been delayed and may not be ready until late next year.
“It’s really, really, really tricky to make sure vaccines are produced and distributed equitably globally, for both moral and economic reasons,” Mark Suzman, executive director of the Bill & Melinda Gates Foundation, told reporters. . Call of December 9.
Suzman noted research that shows that broad access to vaccines could provide significant economic benefits to all countries and save many lives. Because rich nations will likely have more than enough doses to vaccinate their entire population, they should consider reallocating some supplies to those most in need, he said.
Mass vaccination has been one of the most successful public health interventions in the world and has played an important role in increasing U.S. life expectancy by more than 50% over the past century. About a third of U.S. deaths in 1900 occurred in children under the age of 5, many of them from diseases such as smallpox, measles, and whooping cough that can now be prevented by vaccination.
Some new vaccines have also had rapid and widespread use, such as vaccines that prevent pneumococcal infections that can cause serious illness in children and adults. The introduction of the shingles vaccine has offered the prevention of painful disease to millions of people over the past two decades.
Veteran of the World Health Organization’s effort to eradicate smallpox, Orenstein often immunized himself in front of entire peoples to alleviate security fears. The agency decided to try to eradicate the disease in 1959, when it was still suffering from many developing countries, but the effort did not start until 1967, when the WHO and its members committed more funds and staff.
The smallpox effort was initially targeted at entire populations, but proved impractical, recalled William Schaffner, an infectious disease specialist at Vanderbilt University who has advised the government on vaccination. The change came when the strategy was changed to identify cases and then vaccinate everyone nearby, sometimes hundreds of households.
This approach of creating a vaccination ring around cases was only possible, however, because smallpox can be a disfiguring disease, which facilitates its identification and spreads relatively slowly.
“It has that reputation of spreading fast, but it’s actually spreading pretty slowly,” Schaffner said. “You also need a fairly close contact for transmission.”
These features allowed vaccination teams to identify patients just when they were becoming infectious and close all transmission opportunities. However, the global effort took two decades to contain the last outbreak in 1977.
A better comparison with Covid could be poliomyelitis, an intestinal virus that sometimes causes serious, permanent illness. Polio is similar to Covid, as only a minority of infected people (about one in 100) get very sick.
This created one of the problems foreseen in the widespread vaccination against Covid: people who do not believe they are vulnerable to the disease may not want to be vaccinated, although it may benefit other people by keeping hospital intensive care units free. and possibly avoiding transmission. of the disease.
However, an important difference with polio is that it can cause serious illness in young children, leaving them paralyzed for life, Orenstein said. This is not like Covid, which mainly affects the elderly and the chronically ill. This has left some parts of the public indifferent.
“We’re getting more than one death per minute, in a few days two deaths per minute,” he said. “It’s very disturbing to see other people’s lack of concern.”
However, even with the spectrum of children paralyzed by polio and a vaccine available for about 65 years, the global elimination of this disease has not yet been achieved. Two countries, Afghanistan and Pakistan, continue to spread due to insufficient vaccination rates, according to the Global Polio Eradication Initiative.
To defeat Covid, “we need to convince people to get the vaccine,” Anthony Fauci, the U.S. government’s leading infectious disease specialist, said in an interview. “If you have a highly effective vaccine and only 50% of people get it, you won’t have the impact you need to bring a pandemic down to such a low level that it is no longer threatening society. And that’s the goal of ‘a vaccine, the same way we did it with measles, the same way we did it with polio, the same way the world did it with smallpox.’
Most standard vaccines provide protection for years or decades. We still don’t know how long the vaccines against Covid will last, Fauci said. And it’s unclear if they prevent transmission along with protection against symptoms, though studies may soon shed light on that.
The logistical and supply chain challenge facing the world today is “more complicated than usual, because for the first time in history we will introduce multiple vaccines against the same target at the same time,” Rajeev Venkayya, president of Takeda Pharmaceutical Co. The vaccine business said in an interview.
This means countries will need databases to track the release and ensure people receive doses at the right times, as well as systems to control for possible side effects and share information with the public, he said.
Initially, countries plan to prioritize the most vulnerable people, as well as health care workers and other critical professionals, who will significantly reduce deaths and suffering, said Venkayya, a former special aide to biodefense to U.S. President George W. Bush.
“But the transmission will not go down drastically at first. It will take time to reach a sufficient level of vaccine-boosted population immunity before transmission can begin to subside.
Potentially, by the middle of next year, countries like the United Kingdom and the United States will be able to see a “true damping of transmission,” he said. “This schedule will be delayed in many other parts of the world that do not have this type of early access to vaccines.”
Unvaccinated populations always threaten to reintroduce the disease in areas where herd immunity appears to have been imposed. Just last year, the annual number of measles cases reported worldwide multiplied by six by about 870,000, the highest number since 1996, according to immunization rates.
The world is likely to see the same level of viral persistence as coronavirus, said Klaus Stohr, a former Novartis AG vaccine executive and WHO official who championed efforts to prepare for pandemics.
“The prediction is pretty clear: the virus will never be eradicated,” he said. “Why? Because there will always be a large proportion of susceptible population in the community.”
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