Chile shifts Covid vaccine drive to second doses amid concerns over first shot's protection

Chile is shifting its Covid-19 vaccination strategy to second-dose delivery while slowing down the delivery of new vaccinations amid concerns about supply shortages and data showing poor protection against a single dose of Sinovac Biotech (SVA.O) Vaccine that formed the backbone of his campaign.

The Andean nation, which has carried out one of the world’s leading vaccination programs against Covid-19, has put more than 13 million shots in its arms and, according to official figures, around 2 million doses in its warehouses as of Monday.

Currently, clinics are handing out an average of 153,000 vaccinations per day – well below March levels – as Chile aims to reach 15 million people, about 80% of its target audience, and aims to create some level of herd immunity by the middle of the year.

This requires 2.3 million people to be vaccinated with a second dose of one of the two vaccines currently used in Chile – from Sinovac and Pfizer Inc. (PFE.N) – and vaccinate another 7.3 million people.

In the past few days, however, according to Reuters witnesses, both vaccines were running low in clinics around the capital Santiago, which turned people away or asked them to wait several hours for more to arrive.

More than 280,000 cans of the Pfizer / BioNTech shot and the first batch of 800,000 AstraZeneca Plc (AZN.L) Doses Chile will receive from the COVAX vaccination program are expected to arrive in the coming week, the government said.

In addition, Chile is working on further supply agreements to keep its vaccination program on track.

The country is due 700,000 remaining doses of the 14.2 million it ordered for Sinovac’s CoronaVac vaccine, which helped fuel a mass vaccination campaign launched in February that Latin America was envied for.

Chile is waiting for almost 8 million Pfizer / BioNTech cans from a supply contract for more than 10 million. The government said the majority will be delivered before the end of September but cannot set fixed delivery dates.

Health Minister Enrique Paris said a strict weekly vaccination calendar by age group has been created to ensure Chile has not used up its supplies before more have arrived.

“I think we have to be calm about it,” Paris told reporters at a briefing on Monday. “We have a lot of agreements with a lot of different companies and the vaccines are still coming.”

Chile, which vaccinated up to 430,000 people a day in March, has reached more than 50% of the 15 million people scheduled to be vaccinated with a single shot by July, while 36% received both doses.

However, the country was hit by a second wave of coronavirus in March, with the end of the summer vacation in the southern hemisphere and contagious virus variants first circulating in the UK and Brazil.

Santiago and parts of the country are strictly closed. Around 7,000 confirmed new COVID-19 cases are reported every day.

“Could be a lot worse”

Unlike countries that are widening the gap between first and second doses to provide some protection to more people, Chile now has priority over the first dose, according to Paris. The country plans to deliver 760,000 second shots this week as data shows that a single dose of the Sinovac shot offers little protection.

Chile published its own analysis last week of the limited effectiveness of Sinovac’s CoronaVac vaccine on its population. The shot was only 16% effective in preventing infection and 36% in keeping people out of the hospital after a dose.

“If we don’t give the second dose, the situation could be much worse,” said Paris.

In comparison, the risk of infection dropped 80% two weeks or more after the first Pfizer / BioNTech shot, according to the U.S. Centers for Disease Control and Prevention.

In addition to the first AstraZeneca doses expected to be received via COVAX, the Minister of Health has signed a contract to purchase 1.8 million doses of a single vaccine from CanSino Biologics, according to Chile (6185.HK).

Rodrigo Yanez, the Chilean vice minister of trade in charge of purchasing Covid-19 vaccines, told Reuters on Friday that the country’s rapid vaccination campaign has made it an “attractive springboard” for vaccine manufacturers to test their wares. He said he was confident he could keep the supply taps open.

Yanez said his team pushed Sinovac to ship an additional 4 million cans and that the first of 4 million cans purchased directly from AstraZeneca should arrive in May.

He said Chile had also spoken to Sinopharm and India about purchasing a shipment of its Covaxin vaccine and was in “advanced” talks with the Russian Direct Investment Fund to get 5 million doses of the Sputnik V vaccine for shipment this year or next to buy.

“We planned to put various vaccines on and off,” said Yanez, adding that Pfizer will be widely used in the program. “We are confident and confident that we can achieve herd immunity by the middle of the year.”

Follow NBC Latino on Facebook, Twitter and Instagram.

Leave a Comment