A health worker administers a jab of the AstraZeneca COVID-19 vaccine during a vaccination drive for people ages 30 to 39 in Mexico City, Wednesday, July 7, 2021. Credit: AP Photo/Marco Ugarte

Mexico is entering its third wave of the coronavirus pandemic, as infections rose by 29% compared to the previous week.

But the country's department said Friday the growth is largely coming from infections among younger, less . Case numbers are now as high as the beginning of the last surge in September; that wave peaked in January and steadily declined until June.

But at present only about 22% of the country's hospital beds are occupied; hospital beds in many parts of the country were essentially filled to capacity during the last wave.

Authorities said the relative decline of serious cases among older people is a result of the country's vaccination campaign, which as of Friday has given at least one dose to about 39% of all adults.

Assistant Health Secretary Hugo López-Gatell said the rise in infections is not due to the arrival of the Delta variant, but rather to an increase in public activity.

Mexico City health authorities said they expect the third wave to peak in August in the capital, which has been the worst hit by COVID-19 in the previous two waves.

Mexico has suffered almost 235,000 test-confirmed deaths, but because the country does so little testing, the government's own figures on excess deaths suggest the true toll is around 360,000 deaths.