South Korean officials are struggling to put herd immunity anxieties to rest, as COVID-19 vaccinations have hit bumpy ground here amid a sluggish rollout and supply shortages.

With only about 3 percent of the 51 million population at least partially vaccinated to date, doubts are setting in over the administration’s proclaimed goal of having herd immunity by November. The administration estimates vaccination coverage of 70 percent would be required to reach that threshold.

Still, achieving that goal “will not be a problem,” acting Prime Minister Hong Nam-ki told the parliament earlier this week as he asked the public to “trust in the government.”

“Korea will have access to enough vaccines to give to more than 18 million people before July,” he said. “Most of our secured supplies are coming in the latter half of the year. There is no question we will reach herd immunity come November.”

On Wednesday 250,000 doses were added to Korea’s Pfizer reservoir, with some 5 million more doses slated for phased delivery in May and June, according to Hong. The country already used up nearly all of its initial Pfizer batch of 117,000 doses, with more than 730,000 people given at least a single dose of the vaccine so far.

AstraZeneca, whose vaccine can only be used for people aged 30 or older here due to blood clot concerns, will also be supplying an additional 3.5 million doses over the next two months, he said. 

But he admitted that 40 million doses of the Moderna vaccine, which were previously announced as arriving in the second quarter, probably won’t be available until August. The administration’s vaccine introduction task force later confirmed to reporters that the shipment would be delayed.

Prospects are murkier for Johnson & Johnson’s vaccine, of which Korea has bought 6 million doses, as regulators in the US and Europe review a rare and severe blood clotting conditon reported among a small number of recipients.

Although the vaccine has been granted conditional approval, its use in Korea could be subject to some restrictions depending on findings in investigations from regulators overseas, an official within the vaccine introduction task force told reporters Wednesday.

It’s unclear when the Novavax vaccine, which can be manufactured locally, will be cleared for approval, as it is now in the middle of its phase 3 trials.

The Ministry of Health and Welfare echoed the acting prime minister’s assurance that November herd immunity will be attainable. The ministry anticipates that some 36 million Koreans will have been “fully vaccinated” by fall, and deaths and hospitalizations will “drop significantly” in summer, when vaccinations of vulnerable groups will be completed.

Yoon Tae-ho, a senior official within the Health Ministry, sought to divert media attention from the vaccination situation in the country during a news briefing Wednesday.

“Lately there seems to be too much media focus on the vaccines,” he said. “But vaccinations are just one pillar of pandemic control. There are other mitigation measures that are just as important, such as physical distancing.”

Son Young-rae, the ministry spokesperson, also took issue with media coverage that was critical of the slow pace of vaccinations, saying the reports were “causing public unrest.”

“COVID-19 vaccines are coming. The nitpicking from some media outlets isn’t going to help anyone,” he told reporters in Tuesday’s closed-door briefing.

Last week, President Moon Jae-in told a Cheong Wa Dae meeting on COVID-19 response he was “confident” vaccine supply uncertainties have “markedly improved.” He also called on health officials to pursue extra deals so that herd immunity will be reached by November “without fail.”

To ease supply issues, the administration is “activating all diplomatic channels,” the Health Ministry said.

Foreign Minister Chung Eui-yong said in a forum held Wednesday that talks were underway with his counterparts in the US for possible cooperation on expanding Korea’s vaccine access. He mentioned that Korea, as an ally, had earlier provided the US with test kits and face masks.

The pace of vaccinations is picking up in Korea, nearly two months since the campaign launched in late February. Over the 24 hours ending Monday at midnight, around 120,000 people were newly vaccinated, which is far greater than the average rate of 27,000 doses administered a day so far.

As of Tuesday midnight, 1,832,004 in Korea had received at least one shot of a COVID-19 vaccine -- 1,093,182 with AstraZeneca’s and 738,822 with Pfizer’s.

By Kim Arin (arin@heraldcorp.com)