TOKYO — The pressure of hosting an Olympics during a still-active pandemic is beginning to show in Japan.

The Tokyo games begin July 23, with organizers determined they will go on, even with a reduced number of spectators or possibly none at all. While Japan has made remarkable progress to vaccinate its population against COVID-19, the drive is losing steam because of supply shortages.

With tens of thousands of visitors coming to a country that is only 13.8% fully vaccinated, gaps in border controls have emerged, highlighted by the discovery of infections among the newly arrived team from Uganda, with positive tests for the highly contagious delta variant.

As cases grow in Tokyo, so have fears that the games will spread the virus.

“We must stay on high alert,” Prime Minister Yoshihide Suga told reporters on July 1. Noting the rising caseloads, he said “having no spectators is a possibility.”

Organizers, the International Olympic Committee and others are expected to meet this week to announce new restrictions because of the fast-changing coronavirus situation.