MEXICO CITY >> Mexico announced a huge bet on Chinese vaccines Tuesday, without making public any information about their efficacy.

Foreign Relations Secretary Marcelo Ebrard said the Mexican government has signed agreements for 12 million doses of the yet-unapproved Sinopharm vaccine and increased to a total of 20 million doses its contracts for the Coronavac dose made by China’s Sinovac.

Deliveries of Sinovac have already started, with the full 20 million doses expected by July. The Sinopharm vaccines are to be delivered between March and June.

The total of 32 million doses, plus at least 4 million doses of the CanSino shot, would dwarf the estimated 5 million vaccine doses Mexico has acquired so far from other sources.

However, Ebrard’s office has repeatedly refused to answer questions about the efficacy of the Chinese shots.

Sinopharm has claimed its vaccine was 79% effective based on interim data from clinical trials, but like other Chinese firms, it has not publicly released its late-stage clinical trial data.

Experts in Hong Kong have assessed the efficacy of the Sinovac vaccine at about 51%. That shot has already been approved for use in Mexico.

The CanSino vaccine has been approved in Mexico and reportedly has an efficacy rate of around 65.7%,

A total of six vaccines have been approved for use in Mexico, which has received relatively small amounts of each. Mexico has administered only about 4.7 million doses of all vaccines, a tiny amount given the country’s population of 126 million.

The government policy sets up the odd situation in which some Mexicans, mainly in urban areas, will receive the Pfizer vaccine, which has around 95% efficacy, while most will get one of the Chinese vaccines with a much lower effectiveness. Mexico has contracts for a total of about 34 million doses of the Pfizer shot, but deliveries have been slow, with less than a tenth of that amount delivered so far.

Amid a dearth of public data on China’s vaccines, hesitations over their efficacy and safety are still pervasive in the countries depending on them.

Inoculations with Chinese vaccines already have begun in more than 25 countries. None of China’s three vaccine candidates used globally have publicly released their late-stage clinical trial data.

Mexico has suffered almost 190,100 confirmed deaths. However, Mexico does so little testing that government excess-death figures suggest the real toll was well above 220,000 at the start of January, when the government stopped releasing that data. Test-confirmed cases total over 2.1 million.