Brazil’s South American neighbours worry a COVID-19 variant will spread quickly and lead to another wave of deaths.
Brazil’s COVID-19 vaccination programme is being put at risk by people failing to show up for their second shot, with 1.5 million people missing appointments for the follow-up dose needed to maximise protection, according to the Health Ministry.
Specialists say that is particularly concerning after a recent real-world study from Chile found that the Sinovac Biotech COVID-19 vaccine, which has accounted for some 80 percent of Brazil’s program, is just 16 percent effective after one shot.
“Without the two doses, we get neither full protection nor a long duration of protection,” Juarez Cunha, head of the Brazilian Society of Immunizations, told Reuters. “We need people to do the full cycle.”
Until this week, more people were dying in Brazil of COVID-19 than anywhere in the world, with President Jair Bolsonaro widely criticised for opposing lockdown measures and pushing remedies like hydroxychloroquine that provide little or no benefit. India has now surpassed Brazil in daily deaths.
In total, COVID-19 has taken more than 380,000 lives in Brazil, which has the world’s second highest death toll behind the United States.
The country’s vaccination programme has also repeatedly missed targets due to a shortage of doses resulting from delivery delays of active ingredients from China and India.
Now, the failure of people to turn up for their second dose is an extra worry.
Specialists and authorities involved in the campaign said the low turnout appeared to be due to poor communication, with people either not realising the importance of the second shot or simply forgetting when they were meant to go.
In some cases, they said, people might also have been put off by a strong reaction to the first dose, which can frequently cause short-lived fever and body aches. There have also been long lines at some vaccine sites, which can be offputting for priority groups vulnerable to COVID-19.
The Health Ministry has said it is aware of the problem but has not outlined what it is doing to address the issue. It did not respond to a request for comment on why so many people were not getting their second dose.
The ministry has said the problems are not due to a shortage of shots, with second doses held back to ensure availability on schedule.
But with so many second doses left over and with the promise of future deliveries, the ministry changed its guidelines last month to allow for all shots to be rolled out as first doses.
That stands in stark contrast with Chile, where the vaccination strategy has shifted to prioritising second doses over getting more people an initial shot.
South America’s largest economy has a proud history of successful vaccination campaigns and polls have shown that the vast majority of Brazilians are keen to get inoculated. But scientists fear the message about second shots is not getting across.
“People need to wake up and hear every day on the radio, on television, that you have to get your second dose, that you can’t miss it,” said Cristina Bonorino, a member of the scientific committee of the Brazilian Society of Immunology.
The study in Chile, which analysed vaccine effectiveness among 10.5 million people, found that efficacy in protecting against symptomatic illness rose to 67 percent from 16 percent with the second Sinovac shot. The AstraZeneca vaccine, which makes up the rest of Brazil’s inoculations, by contrast, is 76 percent effective two weeks after the first shot.
“If a person doesn’t get their second dose, there’s no guarantee at all that the immunisation will work,” Bonorino said.