New Jersey Governor Phil Murphy warned that new coronavirus infections were forecast to rise before the start of summer, and potentially set new records, if the state is unable to bring a resurgence in cases under control.

Updated models from New Jersey’s health department forecast that under a “moderate case” scenario, new infections could hit 5,445 a day on April 18 and, on the same day, hospitalisations could top out just below 3,000. New cases would not be expected to drop below 3,000 a day “until mid-June at the earliest, while hospitalisations would have eased to just over 1,000 by late July.

The “high case” model forecasts that new infections could exceed 8,000 a day in mid-May and then again in mid-June, while hospitalisations could be expected to “settle into a range of 3,500 during that period.

New Jersey has averaged about 4,400 cases a day over the past week, according to data from the US Centers for Disease Control and Prevention, down from a record rate of 7,877 on January 8. 

There are 2,463 people currently in New Jersey hospitals with coronavirus, according to health department data. Hospitalisations topped out at more than 3,800 on December 23 during the state’s winter surge, but peaked at 8,270 on April 15 last year, according to Covid Tracking Project data, when New Jersey was among those states to be hit hard during the early stages of the pandemic in the US.

Murphy reiterated that the forecasts “were models, not certainties” and that outcomes could be improved through changes in behaviour and an effort to “push through our fatigue and refocus”. But the figures cast a shadow over a vaccination rollout in the state that is among the better-progressed in the country. 

About one-third of New Jersey’s 8.9m residents have received at least one vaccine dose, according to data on Wednesday from the CDC. That is the eight-highest rate in the US and compares to a state average of 29.8 per cent. New Jersey has fully vaccinated 18.7 per cent of its total population, the equal-16th highest in the country and compared to a state average of about 17.4 per cent.

The moderate case scenario modelled by New Jersey’s health department makes several assumptions, including an average vaccine efficacy rate of 95 per cent against all variants. The high case model assumes a vaccine efficacy rate of just 65 per cent and that people will “lower their guard with the warmer weather”.