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BUENOS AIRES, Argentina — More vaccines have been authorized in Latin American countries than anywhere else in the world. However, there is no linear relation between the number of approvals in a country and the vaccination coverage of its population, according to a review of the COVID-19 Vaccine Tracker and Our World in Data databases conducted by Medscape Spanish Edition. The number of approvals reflects the difficulties that the region has had ensuring that sufficient quantities of vaccines are available, experts say. One reason for supply issues is that core countries accepted the first batches that made it to market. Another is that there have been delays in the delivery of doses promised under the COVAX risk-sharing mechanism.
On February 2, the director of the Pan American Health Organization (PAHO) called the Americas the “most unequal” region in the world. At that time, Latin America had, on average, 5.4 approved vaccines per country, compared with Asia’s 5.0, Europe’s 4.7, Africa’s 3.8, and Oceania’s 2.3. To put these numbers in context, the United States has only three. Moreover, one-third of the region’s countries have at least seven approved vaccines; that proportion is 22% in Asia and barely 5% in Europe.
Mexico, with 10 vaccines approved, ranks first in Latin America. Worldwide, it ranks fourth, behind Indonesia, Iran, and the Philippines, each of which has 11. On December 12, 2020, Mexico granted its first emergency use authorization to Comirnaty (Pfizer-BioNTech), and became the fourth country in the world to approve that product. Since then, other vaccines — Vaxzevria (Oxford/AstraZeneca), Sputnik V (Gamaleya), CoronaVac (Sinovac), Convidecia (CanSino), Covaxin (Bharat Biotech), Ad26.COV2.S (Janssen/Johnson & Johnson), Spikevax (Moderna), Covilo (Sinopharm), and Abdala, a vaccine from Cuba (Center for Genetic Engineering and Biotechnology) — have been authorized.
However, despite all the options, only 59.8% of the Mexican population has completed the primary vaccination series, making it 11th in the region.
“The government set out to buy all kinds of vaccines to ensure supply. But that’s caused logistical issues in terms of administration. We’ve had to combine the vaccines in various ways,” said Alejandro Macías Hernández, MD, an infectious diseases specialist in charge of the Microbiology and Infectious Diseases Department at the University of Guanajuato in León, Mexico.
But there really aren’t a lot of findings in the literature on the combination approach. “The main accepted combinations in the literature pertain to the Pfizer–BioNTech, Moderna, and Oxford/AstraZeneca vaccines,” he told Medscape Spanish Edition. “The other combinations used have been based more on ‘real-world’ evidence.”
The situation is similar in Argentina, which is tied with Nicaragua for the second-highest number of approved vaccines in Latin America. Eight vaccines have been approved for emergency use, and one booster, and using a heterologous series has sped up coverage.
Comirnaty was the first vaccine to be authorized in Argentina, as it was in Mexico, but administration outside of clinical trials only began in September 2021. The second vaccine approved — Sputnik V, on December 23, 2020 — became the cornerstone of the vaccination campaign in the first half of 2021. The next vaccines to be approved were, in chronological order, Vaxzevria, Covishield, Covilo, Convidecia, Spikevax, and Sputnik Light. (The COVID-19 Vaccine Tracker mistakenly includes CoronaVac.)
Forced to Explore Other Alternatives
Argentina has the fourth-highest rate of primary vaccination coverage in Latin America, at 77.8%, behind Chile, Cuba, and Uruguay, which have, respectively, six, four, and three approved vaccines. In 13th place is Nicaragua, with just over half of its population fully vaccinated.
“The countries that approved fewer vaccines are those that were guaranteed a very significant supply of the first approved vials, especially of the mRNA vaccine and then of the Oxford/AstraZeneca vaccine. In contrast, Argentina and other countries had to buy supplies of other vaccines and explore other alternatives,” Analía Urueña, MD, director of the Center for Studies for the Prevention and Control of Communicable Diseases at ISALUD University in Buenos Aires, told Medscape Spanish Edition. She is also one of the coordinators of the Vaccine Confidence Project Latin America.
In April 2021, the World Health Organization criticized the “shocking imbalance” in the distribution of vaccines and decried the fact that, of the 700 million vaccine doses administered globally, rich countries had received 87.0% and low-income countries, just 0.2%. Shipments of vaccines from the Serum Institute of India were delayed because of an outbreak of the Delta variant in that country, which also delayed COVAX deliveries.
Have the many vaccines available led to what marketers call “choice paralysis”? Or could it be that, because there are so many options, people have the impression that some vaccines are better or safer than others, thereby undermining overall confidence in this public-health intervention? Urueña doesn’t think so because, except in isolated cases, people were vaccinated with the product that was available in their jurisdiction; unlike in the United States, the decision of which vaccine to get was not made at the individual level.
Findings from the Bunge y Born Foundation 2021 vaccine confidence study, conducted in Argentina, were presented earlier this month. There does not appear to be any correlation between the number of vaccines approved and the population’s confidence, reported principal investigator Guadalupe Nogués, PhD. And, in general, acceptance of COVID-19 vaccines has been shown to be very high.
“Vaccination strategies were dynamic and began to show evidence that vaccine interchangeability not only was possible, but also more effective” in terms of immune response, Urueña told Medscape Spanish Edition. “That helped to build confidence that it wasn’t necessary to stick to the same vaccine for all doses of a primary series.”
Other Latin American countries that have an above-average number of approved vaccines are Brazil, Paraguay, and Venezuela, each with seven, and Bolivia and Chile, each with six.
The COVAX “Fiasco” and Market Realities
“Problems can be traced back to the reliance that was put on a single purchasing mechanism, COVAX, which turned out to be a fiasco,” said Sonia Arza Fernández, MD, head of the Department of Preventive Medicine at the School of Medical Sciences of the National University of Asunción in Paraguay.
“In addition, the lack of foresight by the authorities when it came to delivery delays impeded efforts to seek alternatives for block purchases with other countries,” she told Medscape Spanish Edition.
“So when we found ourselves in the midst of waves of COVID deaths, vaccinating people mostly with donated doses, we felt justified moving toward approval for various vaccines. To this day, we continue to lag behind in terms of vaccination coverage, and purchases through COVAX are not meeting the country’s needs,” she added. Just 43.6% of Paraguay’s population has completed the primary vaccination series, according to Our World in Data, which is the second-lowest rate in Latin America, just ahead of Guatemala.
The fact that Latin America has a higher number of approvals than other regions of the world reflects the lack of availability of vaccines at the beginning of the pandemic, said Jarbas Barbosa, MD, PhD, assistant director of PAHO, during a weekly press briefing.
“We had some manufacturers that, for market reasons, sought out stronger markets that were already prepared to buy their vaccines. In that situation, many other manufacturers looked to Latin American countries as places where they could submit their products and obtain approval,” Barbosa told Medscape Spanish Edition.
The most notable examples are the vaccines from Russia and China. To date, Sputnik V has been approved in Russia, two-thirds of the countries in Latin America, and a handful of countries in Europe (mostly Eastern Europe): Albania, Belarus, Bosnia and Herzegovina, Hungary, North Macedonia, Montenegro, San Marino, Serbia, and Turkey.
And except for Honduras and Costa Rica, practically all other countries in the region have approved vaccines developed by Chinese pharmaceutical companies: Sinovac’s CoronaVac and Sinopharm’s Covilo (also known as BBIBP-CorV). As was the case with Sputnik V, those two companies had limited success getting their products into the European market.
But diversity has its advantages. “Some noteworthy studies have shown that when a country has different vaccines available, it can more easily manage vaccination series by combining one vaccine for the primary vaccination with another for the third dose or booster,” Barbosa concluded.
On February 15, 1.5 million doses of the Pfizer–BioNTech vaccine, donated by Spain, and 150,000 doses of the Moderna vaccine had been shipped to Ecuador and Haiti, respectively, according to PAHO. With those deliveries, COVAX has distributed 100 million doses to Latin America and the Caribbean. Still though, coverage remains uneven throughout the region, PAHO noted.
Macías Hernández, Urueña, Nogués, and Arza Fernández disclosed no relevant financial relationships.
This article originally appeared in the Spanish edition of Medscape.
Follow Matías A. Loewy of Medscape Spanish Edition on Twitter @MLoewy.
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