Executives from the major COVID-19 vaccine producers have said to expect a big jump in the delivery of doses over the coming month. Pfizer and Moderna executives told a congressional committee on Tuesday that they expect to complete delivery of 300 million doses each by summertime. Johnson & Johnson says it is aiming to provide an additional 100 million doses. That would be more than enough to vaccinate every American adult. President Joe Biden has promised that anyone in the U.S. who wants to get vaccinated will be able to do so by the end of July. The death toll in the U.S. from the coronavirus has now surpassed 500,000.