JOHANNESBURG (AP) – Many world leaders at this week’s virtual U.N. summit are pleading for a COVID-19 vaccine to be made available and affordable to all. But with the U.S., China and Russia opting out of a collaborative effort to develop and distribute a vaccine, the speeches are likely in vain. More than 150 countries have joined COVAX, in which richer countries buy into potential vaccines and help finance access for poorer ones. But the absence of Washington, Beijing and Moscow means the response is short of truly being global. Kazakhstan’s leader says, “We must take the politics out of the vaccine.”