MADRID (AP) — People who received a shot of the Johnson & Johnson COVID-19 vaccine will be offered a second dose from a different drug maker, Spain’s health authorities said on Wednesday.

Spain’s health ministry said that the Johnson & Johnson vaccine has proven to be less effective than other vaccines. So Spaniards who have received it will now be offered a booster shot of either the Pfizer-BioNTech or the Moderna vaccines once three months have passed.

Only 1.9 million of the 37 million Spaniards who have been vaccinated have received the J&J shot.

Spain boasts one of the most successful voluntary vaccination campaigns in the world with 88% of its target population of 12 years and up fully vaccinated.

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