Some experts believe that the US only needs to vaccinate another 30 million to 40 million people to repel Covid-19 without public immunity.
“America only needs 10-15% more vaccinations,” said Eric Topol, professor of molecular medicine at the Scripps Research Institute in La Jolla, California.
44% of the US population has received at least one dose of the vaccine and 31% is fully vaccinated. When a certain number of people are vaccinated, Covid-19 cases will plummet, spreading more slowly enough to prevent large outbreaks.
“When vaccinating 50% of the population, the cases will be significantly reduced. By then, half of the population at risk of disease is protected. That means a lot,” said Professor Robert Wachter, chief Faculty of Medicine at the University of California, commented.
Topol cites the example of California, where the vaccination rate is 50%. The state’s average daily number of infections over the past 7 days is currently only 4.3 cases per 100,000 population, compared with 5.5 cases in the first days of April and 9.6 cases in the last week of February.
“We can see the first positive signs here. California is the most populous state and looks better than ever since the outbreak,” said Prof Topol.
In San Francisco, where 72% of people 16 years of age and older received at least one shot, there were only 6 Covid-19 deaths in April out of a population of 882,000. Dr Grant Colfax, director of the San Francisco Department of Public Health, said that the decline was due to the city’s focus on the vaccination campaign and implementation of infection reduction measures.
Overall, the number of infections nationwide is declining, especially in the age group with high immunization rates. Two-thirds of Americans 65 and older are fully vaccinated. According to the Centers for Disease Control and Prevention (CDC) on April 28, two doses of the Pfizer or Moderna vaccine can reduce the risk of hospitalization in this age group by 94 percent.
Another example is Vermont, which has a 56% immunization rate, the third highest in the nation. Covid-19 cases here fell 60% in April, even among young people who received less vaccination, according to Vermont Commissioner Michael Pieciak, Covid model and data manager- 19 state.
Monica Gandhi, an infectious disease specialist at the University of California, is working with scientists to build a disease model. They predict new cases of Covid-19 in the US will drop to 10,000 on May 29 or earlier. The number of infections per day in the US is currently around 48,000. This is the first time since October 2020, cases are lower than 50,000.
To vaccinate 30 million to 40 million people more, America will need a lot of communication and education work, but Gandhi believes the country can do this.
“I believe we can convince 60% of adults to get vaccinated.” Topol added: “Anyone can get the shot. We just need to vaccinate another 40 million people.”
However, there are people who do not support this point of view. Dr. Paul Offit, director of the Center for Vaccine Education and infectious disease specialist at Philadelphia Children’s Hospital, believes that to control Covid-19, nearly 80% of the population needs immunity. Considering vaccine immunity and natural infections, he thinks that 50% of the US population is already resistant to the virus.
According to Dr. Offit, the decline in the number of infections nationwide is due to immunization, immunity through infection, and seasonal weakening of the virus.
“Covid-19 is essentially a winter virus. We need to vaccinate another 100 million people before next winter,” he said.
Other experts believe that it is important to understand the difference between the immunity threshold that helps the number of cases to decrease and immunity in the community. To achieve community immunity, 80% to 90% of the population needs to be vaccinated or be immune from infection.
“I fear that while injection rates are very high in many places, some are lower. Even though the total number of cases is reduced, the risk of outbreaks remains,” says Barry Bloom, immunologist and expert. Global Health at Chan Harvard Medical School.
In Westchester, New York, where 52% of people have received at least one dose of the vaccine. The number of cases, hospitalizations and deaths is declining, said Dr. Dial Hewlett, medical director of the department of disease control. However, he worries that as the rate of infection decreases, people who have not been immunized will become more afraid of being vaccinated.
“Imagine you just put out a fire over the entire forest, but the fires can still make the fire start again. So we should not be negligent and subjective,” Hewlett said.
Mai Dung (According to the USA Today)